1. Field of the Invention
This invention relates to an element and to a multifunctional catheter probe for carrying out intracorporal measurements, in particular for the measurement of the closure force of a sphincter, according to the introductory parts of the independent patent claims.
2. Discussion of Related Art
Known catheters are used for measuring the closure force of sphincters, such as the esophageal sphincter, the sphincter oddi, the urethral sphincter and finally the anal sphincter. With this, the applied probes are different in their shaping, in particular in length and diameter, depending on the closure muscles to be measured.
With the use of electronic sensors in catheter probes, one may get measurements for the diagnosis in various regions. Typically, achalasias in the region of the esophagus, the urethra or the colon may be ascertained with intracorporal catheter probes, as well of course also pressure or pH-value readings in hollow organs, very generally.
Thus, it is particularly those measurements which, according to a manometric method, permit the measurement of the closure force of the sphincter, which are commonly applied. The measurement probes for manometric methods are usually disposable probes. The electronic measurement probes which may be used several times and which measure the closure force, in particular via piezoresistive measurement sensors, may in practice be used as often as possible, but are relatively expensive. With this form of probe, the pressure sensor is located in a balloon-like chamber which is filled with gel or a fluid to measure the produced pressure of the sphincter all around. This in principle however only leads to conclusions with regard to the pressure produced by the sphincter in its entirety, but not with regard to the locally occurring maximal pressure.
A further known device operates with a balloon catheter with which the closure force of the sphincter acts on the balloon and the closure force may be measured from this in a manometric manner. Such a solution requires no monitoring of the leakage which passes through the sphincter region, but the compressibility of the air is a problem. The temperature dependence can be an essential problem and also the total length of the measurement probe can be a problem.
The use of catheter probes for various applications with multiluminal flexible tubings has been known for years, such as taught by U.S. Patent Documents U.S. Pat. No. 6,547,758-B or US-2003/0130679-A.
Perfusion catheter probes for measuring the closure force of a sphincter are known from U.S. Patent Documents US-2001/0053920 and U.S. Pat. No. 4,809,710. Both catheter probes have peripheral measurement lumens which comprise measurement openings which are directed radially outwards and which are arranged distributed over the longitudinal direction of the probe between the proximal and the distal end. According to U.S. Patent Document U.S. Pat. No. 4,809,710, the measurement lumens are arranged about the central feed lumen in a helicoidal manner. In this manner, it becomes possible to arrange the measurement openings either distributed about the periphery or in the axial direction at the same angular position directly behind one another. The latter permits the anal sphincter to be examined over its entire length with regard to the closure force.
Balloon catheter probes for examining the closure force of the sphincter have been known for years, such as taught by U.S. Patent Documents U.S. Pat. No. 4,776,347, U.S. Pat. No. 5,776,081 and European Patent Document EP-A-0′,935′,977. Since with balloon catheters, practically only one centrically arranged lumen is provided in the catheter balloon for supplying water, and a second lumen for supplying pressurized air, usually here suitably considerably more simple, mostly only flexible tubings with two or three lumens are applied.
Also there are known measurement probes with which one or more radially outwardly directed openings are present on a flexible tubing, the openings being closed in each case by a membrane. The corresponding measurement lumens are filled with a fluid, and a pressure on the membrane leads to a pressure change in the corresponding lumen, so that it is possible to again measure the closure force of the sphincter in a manometric manner.
For the manufacturer of sphincter measurement probes, this means offering a large number of measurement probes of a different construction type and have a correspondingly large storage space, but despite this may practically not keep any complete manufactured probes in stock.
Added to this is the fact that the manufacture of measurement catheters of multiluminal flexible tubes with which lateral openings are incorporated at a later stage, and whose passages are closed by a suitable stopper, is complicated.